When I joined the Air Force in 1977, I took seriously the oath to protect and defend the Constitution and the country it created.

Our national heritage derives not just from principles of government but from the land that sustains us. America’s wild places — our ancient forests, colorful deserts, rushing rivers and snowcapped mountains — give us places to explore and enjoy. I’d like to see that land remain as public as possible and as unspoiled as possible. That’s why I recently joined more than 1,000 retired military leaders who signed a letter to President Donald Trump urging him to protect the boundaries of national monuments like Gold Butte and Basin and Range.

“We ask that you ensure that all Americans, including veterans, continue to have opportunities to find solitude, hunt, recreate, and bond with their families on our protected public lands, including all of the national monuments currently under review,” the letter reads.

In September, U.S. Interior Secretary Ryan Zinke delivered a report to the president advocating that multiple monuments be shrunk or their management be changed to clear the way for commercial development, including oil and gas drilling, mining, and ranching. The president followed through by significantly reducing two national monuments in Utah: Bears Ears and Grand Staircase-Escalante, leaving important historical, cultural and scientific resources at risk.

Days later, The Washington Post released documents showing that a company owned by Canadian uranium giant Cameco lobbied extensively for the Bears Ears cuts to make it easier to access radioactive ore being milled nearby.

Dozens more monuments could follow, so we want the president to know veterans who fought for this country want to protect the land as well as the people, and we oppose downsizing or otherwise altering any more national monuments.

John Dalla retired as staff sergeant following a 19-year career in the Air Force. He lives near Las Vegas.